Re: assembly language and reverse engineering


"Herbert Kleebauer" <klee@xxxxxxxxx> wrote in message
news:4753C1D8.EC69E81E@xxxxxxxxxxxx
cr88192 wrote:

one would be better off learning assembly on linux than they would be on
DOS.
anymore, about the only real use for real mode is for getting into
protected
mode...

Why does this myth never die? Please explain what you can learn
in Windows assembly programming what you can't learn when doing
assembly programming in DOS (and we are not speaking about the
Windows API but about assembly programming).

the point is not what you can't learn, but what you have to learn in the
process.

dos would force you to learn more than windows or linux (for example, one
has to learn about segment registers, ...).

learning real mode programming, would take longer, and teach things that,
unless one is doing OS coding, are not terribly useful...


Assembly programming
means to generate an instruction stream for the CPU and not for
the OS. And the CPU is the very same whether you use Windows, Linux
or DOS as an OS.

but, real mode is real mode, and pmode is pmode.
the way we use the CPU is different, and so is the mod/rm structure.

learning RM first could leave one thinking they can use only SI, DI, BX, or
BP in memory references...

or, at least until they come to understand things like:
mov eax, [ecx+edx*4]

....



.

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